1. Field of the Invention
Generally, the present disclosure relates to the manufacture of semiconductor devices, and, more specifically, to unique high performance inductor/transformer structures and methods of making such inductor/transformer structures.
2. Description of the Related Art
The fabrication of advanced integrated circuits, such as CPUs, storage devices, ASICs (application specific integrated circuits) and the like, requires a large number of circuit elements, such as transistors, capacitors, resistors, etc., to be formed on a given chip area according to a specified circuit layout. Passive elements are very important components of many integrated circuit products. Passive elements can be simplistically separated into distributed elements and lumped elements. Examples of distributed passive elements include transmission lines, waveguides, antennas, etc. Examples of lumped passive elements include inductors, transformers, linear and variable capacitors, resistors, etc. Passive elements are indispensable in analog and RF systems. Such passive elements may be used in numerous ways, e.g., in matching networks, LC tank circuits, attenuators, filters, decoupling capacitors, loads, or die antennas and antenna reflectors, etc.
An inductor is one of the most critical elements in RF and microwave circuits for high frequency wireless applications. If the inductance of the inductor is too low, the lumped circuit will not reach the desired performance targets. Spiral inductors that have a high inductance value are commonly in demand for wireless system-on-chip (SoC) and radio frequency integrated circuits (RFIC).
Existing inductor structures are typically manufactured in one of the upper metallization layers of an integrated circuit product. In one example, an inductor may comprise a plurality of laterally spaced apart solid metal structures, e.g., copper, that are positioned in a layer of insulating material. Such a side-by-side configuration of the components of the inductor means that the inductor consumes a significant amount of plot space. Moreover, using such prior art inductor designs, achieving sufficient levels of inductance could sometimes be problematic.
The present disclosure is directed to unique high performance inductor/transformer structures and methods of making such inductor/transformer structures that may reduce or solve one or more of the problems identified above.